The invention is based on a shock absorber as defined hereinafter. Shock absorbers are already known to applicants in which a damping action is variable by means of an electromagnetic adjuster. The adjuster includes a magnet coil and a control slide, and the control position of the control slide determines the throttling of the pressure fluid being exchanged between the work chambers.
In the version known to applicants, a throttle cross section in a throttle passage is opened to a variable extent depending a control position of a control slide. When there is maximum current to the magnet coil, the control slide is located in a terminal control position, in which a maximum-sized throttle cross section is uncovered in the throttle passage. The maximum throttle cross section means minimum damping by the shock absorber. Without current, the control slide is in another terminal control position, in which a minimum-sized throttle cross section is uncovered. The minimum cross section represents maximum damping by the shock absorber in the latter position.
In the event of an electrical defect, such as if the magnet coil fails or if a supply lead to the magnet coil breaks, maximum damping of the shock absorber is obtained. Although maximum damping by the shock absorber is necessary in some extreme situations, still in the case of a defect it is not an optimal compromise.
The adjuster may be provided either in the cylinder or outside the cylinder.